At one point during an hours-long House Judiciary hearing on Thursday, Illinois Democrat Luis V. Gutiérrez called President Barack Obama's recent decision to hold off on taking executive action to curb deportations a "grand gesture" of his willingness to give Republicans more time to advance immigration legislation on their own.

But the Republicans who gathered to hear testimony from Homeland Security Secretary Jeh Johnson weren't impressed by the administration's olive branch. Instead, GOP lawmakers hammered Obama's immigration point-man over what they see as ongoing efforts to supersede the legislative branch.

Rep. Steve King, R-Iowa, one of the leading voices against any legislative effort to rewrite the nation's immigration code, called the pending release of Johnson's recommendations a "sword of Damocles that's hanging over our heads."

Rep. Lamar Smith, R-Texas, challenged Johnson on the dictionary and legal definitions of the term "amnesty," while Rep. J. Randy Forbes, R-Va., sarcastically thanked Johnson for being unable to answer a question on whether it was Homeland Security policy that any undocumented immigrant who claims to have denounced a prior affiliation with a criminal gang would be released from federal custody.

Rep. Doug Collins, R-Ga., disagreed with Johnson's characterization that there was any "legal ambiguity" for some undocumented immigrants living in the United States.

"We can't deport 11 and a half million undocumented immigrants," Johnson said. "You and I both know that."

"Did I ever say that?" Collins shot back.

"What is the difference for prosecutorial discretion and a wholesale failure to enforce the law?" asked Rep. Trey Gowdy, R-S.C., himself a former federal prosecutor.

Judiciary Chairman Robert W. Goodlatte, R-Va., spelled out the concerns within the House GOP conference explicitly.

"President Obama has asked Secretary Johnson to 'perform' an inventory of the department's current enforcement practices to see how it can conduct them more 'humanely.' These are simply code words for further ratcheting down enforcement of our immigration laws," Goodlatte said during his opening remarks.

Johnson stayed composed and collected during some of the more heated exchanges with lawmakers, defending the administration's commitment to detaining undocumented immigrants with serious criminal records as well as ongoing efforts to rethink some of the policies that can result in the separation of loved ones and the fracturing of families.

"I am appointed by this president ... my loyalty is to him [but] I have a higher obligation to the law," Johnson told Judiciary Committee members. "I will not participate in something that I do not believe squares with my legal obligations. ... The district judge who swore me in administered the oath to me, said to me, 'You are about to take an oath. Your oath is not to the Department of Homeland Security, your oath is to the Constitution. I believe that very passionately."

Democrats used their audience with Johnson as an opportunity to emphasize the need to pass an immigration overhaul bill that would include some pathway to citizenship or legal status for the nation's more than 11 million undocumented immigrants.

"We have heard nothing but excuses [from Republicans] for not doing immigration reform," said Judiciary ranking member John Conyers Jr., D-Mich.

Some members of the minority party implored Johnson to address in his recommendations to Obama the fact that many of the undocumented immigrants in detention are being held for the felony of reentering the country after being deported — to be reunited with their families.

"They are doing what former [Florida] Gov. [Jeb] Bush described as an act of love," said Rep. Zoe Lofgren, D-Calif. "They are trying to come back to be a parent to their children."